remove(hooks): Kill off old hook that checked compile flags.

This did things like verify that things were linked with gold (which we
don't do) and other checks. We don't have a need for it kill it.
remove(tests): Remove old ChromeOS test utilities

None are useful or relevant to us.
remove(symbols): Kill off scripts for managing ChromeOS debug symbols
remove(cruft): Kill a few more things that aren't used
Merge pull request #252 from marineam/clean

Clean out some old ChromeOS junk